Microbial organisms produce fatty acyl-CoA and fatty acyl-CoA derivatives, such as fatty alcohols, fatty acids, fatty aldehydes, fatty esters, fatty acetates, wax esters, alkanes, and alkenes. Such fatty acyl-CoA derivatives may be used to produce a wide variety of products, including jet and diesel fuels (e.g., biodiesel), chemical surfactants, polymers, nutritional supplements, pharmaceuticals, food additives, cosmetics, and personal care products.
Fatty acids are a principal component of cell membranes and are used by organisms for energy storage. Fatty acids are metabolized by β-oxidation of fatty acyl-CoA, or conversely, fatty acids are synthesized from acetyl-CoA by fatty acid synthase multi-enzyme complexes. Fatty alcohols are the reduction products of fatty acyl-thioester substrates (e.g., fatty acyl-CoA or fatty acyl-ACP), and like fatty acids, can be produced enzymatically by cultured cells. Enzymes that convert fatty acyl-thioester substrates (e.g., fatty acyl-CoA or fatty acyl-ACP) to fatty alcohols are commonly referred to as “fatty alcohol forming acyl-CoA reductases” or “fatty acyl reductases” (“FARs”).
The commercial production and recovery of fatty alcohols from microbial organisms is challenging, in part because fatty alcohols are not very stable in many microorganisms. The fatty alcohols (e.g., hexadecanol) can be used as a carbon source for the microorganism, and may thus be metabolized by the microorganism before recovery for commercial purposes. The fatty alcohols are likely degraded by enzymes that catalyze the oxidation of alkanes to fatty acids (via fatty alcohols). Fatty acids can then be further degraded to acetyl-CoA by enzymes in the β-oxidation pathway or converted to storage lipids by a set of acetyltransferases.
Accordingly, there is a need for microbial organisms for the efficient production of fatty acyl-CoA derivatives.